Influence of different fluidization and gasification parameters on syngas composition and heavy metal retention in a two-stage fluidized bed gasification process.

Abstract

Herein, we investigated the influence of gasification and fluidization parameters on the H2 content of syngas and the retention of heavy metals (Cu and Pb) in a bed material during a two-stage fluidized bed gasification process. The results indicated that a temperature of 900°C in both stages resulted in the highest H2 content (32.4mol%) in syngas. When different equivalence ratios (ERs) were investigated, it was found that the highest H2 content in syngas (25.4mol%) was achieved at an ER of 0.3. A particle size of 0.46mm in the fluidized bed led to an increase in the H2 content of syngas. Moreover, increasing the operating gas velocity led to an increase in the H2 content of syngas. The heavy metal concentration in the bed material was the highest at 500°C. When the influences of different particle sizes and operating gas velocities were compared, it was observed that a particle size of 0.46mm and gas velocity of 1.5U/Umf resulted in increased heavy metal concentrations in the bed material, which indicates that the reduction in the particle size and the increase in the operating gas velocity enhanced gasification and improved the retention of heavy metals.